ittjv

iTrader: (32)

Gotcha... there is so much that goes into a loose condition. You can try narrowing the rear a touch to lock it down and this will give you more rotation (steering) at the same time. You can also try lowering the roll center in the rear, but that won't really give you steering. You may have to do both to get to your desired state. If your car is close, you'll be able to feel small, small changes... like going one block smaller, front (rf) and rear (rr), or removing .5mm spacers from the axles/hubs. Give it a try... it could also be your choice of body and how you cut the wing.
- Jose

b3master

iTrader: (1)

nubs

iTrader: (2)

Anyone using the stealth line of SMJ springs and if so, how do they compare?

Raman

iTrader: (94)

elbicho

54886 TRF419 Suspension Upgrade Set

Maybe we can upgrade our 419s to something like 419'5

​​​​will see.

Raman

iTrader: (94)

snopro31

iTrader: (57)

herrokero

How much oil are you filling the diff with? Filling above the small gears?

snopro31

iTrader: (57)

nubs

iTrader: (2)

Hey Sno. The shim goes under the big bevel gear above the o-ring.The idea is to create as little slop as possible between the outdrive and the pin holding the outdrive to the gear diff. The trick is to not make it too tight because that creates friction. Sometimes people think their diff is leaking when in reality they accidently put diff fluid inside the openings between the two diff housings. Make sure that when you are building the diff, those holes don't get diff fluid in them. Additionally, make sure to very gently sand down flat the edges of the diff housings. Do you put green slime on both sides of the gasket? Do you use the alignment marks on the outside of the gear diff housings? Also, make sure you do not cover the entirety of the gears with diff fluid. You should only fill up to the cross joint. If you go above that amount, you will leak. One last question, what does it look like when your diff leaks. Does it get all over your body? Or does it stick around the outdrives?

snopro31

iTrader: (57)

rc_square24

iTrader: (9)

Just sharing a bit of my thoughts about gear diff assembly and types of orings, it's just my personal experience so feel free to discuss.

Parts Preparation

• Drill the 4 screw holes with 2mm bit to release any trapped oil that may escape during assembly (although there shouldn't be any if filled right).
• Pre-tap the holes with the supplied screws, then chamfer the edges around the holes with a hobby knife as they may bulge slightly after tapping.
• Lightly wet sand the flat surface of the bottom case where the gasket is seated to remove any irregularities, I aim for a uniform matte finish.
• Lightly wet sand the diff case bearing surfaces for the 10mm bearings, sometimes they might be too tight and cause binding.
• Lightly sand the flat side of all gears to remove any irregularities.
• Bearing Holders/Cams: I find that the 10mm bearings sit quite tightly on the bearing holders/cams and since the hole on the plastic part is about the same diameter as the inner bearing race, it makes it difficult to pull apart. I used a body reamer to enlarge the hole by around 0.5-1mm, this allows me to fit a 7mm nut driver to push the bearings out.

Dry Fitting

• Xray 972050 Orings: the silicone on these have a larger cross sectional diameter than regular P5 orings. When inserted it is compressed to form a seal. As mentioned, due to this there is more drag. Since the oring protrudes slightly above the recess, only a 0.1mm large shim is required to take up the play, any thicker will bring more drag. As you can see from the sketch below, the oring is thicker so the only purpose of the shim is to retain the oring, the bottom of the shim doesn't sit completely on the case. With these orings I have not experienced any leak from the outdrives (5,000 / 7,500 / 10,000).
• Tamiya (Red 42259) / Axon (Clear OR-GD-004/ Black OR-GD-001) Orings: As sketched below, the overall dimensions of these orings are smaller than the recess of the case, so adding shims above the recess (as per manual) does not compress the oring to form a seal (the inner edge grabs around the shaft but the outer edge has no contact against the wall of the recess, and the top of oring does not protude above the recess). For this, first shim the outdrive without the oring to reduce the play of the outdrive, usually 0.2mm is enough, then place a regular 0.1mm or 0.13mm shim (5mm wheel axle shim) above the oring (between large shim and oring, not shown in sketch) until you feel a slight drag (which means its compressing the oring to form a top/bottom seal). With this combination I have no leaks as well so far (3 runs), but I need more runs to confirm (10,000).

Assembly

• Lube up the parts (oring, recess, shaft, bushing), I use Axon Gear Diff Grease but any thick grease should do.
• If using Xray orings, since they are much larger I recommend to first push the greased oring into the recess and place the shim over it to keep in place, then insert the outdrive and retain with the pin.This prevents the oring from popping out when the outdrive is inserted.
• Use a scale to fill oil into the case with only the bottom large bevel installed, and only after 1.5g of oil is filled and settled I drop in the cross shaft and small gear assembly to reduce the amount of trapped air. Tap the cross shafts a bit, when settled the oil should end up more or less around the top level of the cross shafts.
• If your scale has auto-off function, it's good to note the weight of the dry assembly to keep track of the oil weight in case it turns off during filling.
• Dab some grease on the lid to prevent the gasket from falling off, with the top bevel installed. Place over the case, spin the outdrive slightly to seat and mesh the gears, fasten screws evenly in a cross pattern, do not over-tighten as the lid may distort and leak.
• With 1.5g of oil I have no overflow during assembly or oil seeping out on the pulley teeth.
• I use 0.2mm shims between the bulkhead and it's top cap (damper stay assembly) to prevent binding/compression on the bearing holders.

*Yokomo 5mm Plastic Shim Set ZC-S50 contains 0.13mm thickness.

rc_square24

iTrader: (9)

It seems your diff is leaking between the two halves of the diff case as opposed to leaking from the outdrive as I've experienced before. The 419 gasket is thick and should conform well to seal properly. I suggest using a scale to control the amount of oil filled instead of eyeballing until you get a feel for it.

Did any excess oil ooze out during assembly? In your situation it may be the excess oil stuck between crevices that are flinging out when the car is run (but gasket is sealing properly), or an actual leak between the gasket. Overfilling may also cause leaks as the internal pressure builds up during diff action.

nubs

iTrader: (2)

Perfect answer. This should be the end of the discussion.

JoeyE

iTrader: (45)

I installed sealed bearings with green slime at the outdrives on the gear diff. No leaks for a couple years. I guess I got lucky.